Use BKE_mesh_apply_vert_coords instead of local defined version

This makes generating modifiers work as well.

source/blender/blenkernel/BKE_mesh.h

@@ -458,6 +458,7 @@ void BKE_mesh_calc_relative_deform(
 /* *** mesh_validate.c *** */
 
 int BKE_mesh_validate(struct Mesh *me, const int do_verbose, const int cddata_check_mask);
+bool BKE_mesh_is_valid(struct Mesh *me);
 int BKE_mesh_validate_material_indices(struct Mesh *me);
 
 bool BKE_mesh_validate_arrays(

source/blender/blenkernel/BKE_modifier.h

@@ -498,6 +498,10 @@ void modifier_deformVerts(
         struct ModifierData *md, const struct ModifierEvalContext *ctx,
         struct Mesh *mesh, float (*vertexCos)[3], int numVerts);
 
+void modifier_deformVerts_ensure_normals(
+        struct ModifierData *md, const struct ModifierEvalContext *ctx,
+        struct Mesh *mesh, float (*vertexCos)[3], int numVerts);
+
 void modifier_deformMatrices(
         struct ModifierData *md, const struct ModifierEvalContext *ctx,
         struct Mesh *mesh, float (*vertexCos)[3], float (*defMats)[3][3], int numVerts);
@@ -516,6 +520,10 @@ struct Mesh *modifier_applyModifier(
         struct ModifierData *md, const struct ModifierEvalContext *ctx,
         struct Mesh *mesh);
 
+struct Mesh *modifier_applyModifier_ensure_normals(
+        struct ModifierData *md, const struct ModifierEvalContext *ctx,
+        struct Mesh *mesh);
+
 struct Mesh *modifier_applyModifierEM(
         struct ModifierData *md, const struct ModifierEvalContext *ctx,
         struct BMEditMesh *editData, struct Mesh *mesh);

source/blender/blenkernel/intern/DerivedMesh.c

@@ -84,8 +84,10 @@
 
 #ifdef USE_MODIFIER_VALIDATE
 #  define ASSERT_IS_VALID_DM(dm) (BLI_assert((dm == NULL) || (DM_is_valid(dm) == true)))
+#  define ASSERT_IS_VALID_MESH(mesh) (BLI_assert((mesh == NULL) || (BKE_mesh_is_valid(mesh) == true)))
 #else
 #  define ASSERT_IS_VALID_DM(dm)
+#  define ASSERT_IS_VALID_MESH(mesh)
 #endif
 
 
@@ -95,6 +97,8 @@ static ThreadRWMutex loops_cache_lock = PTHREAD_RWLOCK_INITIALIZER;
 static void add_shapekey_layers(DerivedMesh *dm, Mesh *me, Object *ob);
 static void shapekey_layers_to_keyblocks(DerivedMesh *dm, Mesh *me, int actshape_uid);
 
+static void mesh_init_origspace(Mesh *mesh);
+
 
 /* -------------------------------------------------------------------- */
 
@@ -891,6 +895,20 @@ void DM_set_only_copy(DerivedMesh *dm, CustomDataMask mask)
 #endif
 }
 
+void mesh_set_only_copy(Mesh *mesh, CustomDataMask mask)
+{
+	CustomData_set_only_copy(&mesh->vdata, mask);
+	CustomData_set_only_copy(&mesh->edata, mask);
+	CustomData_set_only_copy(&mesh->fdata, mask);
+	/* this wasn't in 2.63 and is disabled for 2.64 because it gives problems with
+	 * weight paint mode when there are modifiers applied, needs further investigation,
+	 * see replies to r50969, Campbell */
+#if 0
+	CustomData_set_only_copy(&mesh->ldata, mask);
+	CustomData_set_only_copy(&mesh->pdata, mask);
+#endif
+}
+
 void DM_add_vert_layer(DerivedMesh *dm, int type, int alloctype, void *layer)
 {
 	CustomData_add_layer(&dm->vertData, type, alloctype, layer, dm->numVertData);
@@ -1265,6 +1283,30 @@ static DerivedMesh *create_orco_dm(Object *ob, Mesh *me, BMEditMesh *em, int lay
 	return dm;
 }
 
+static Mesh *create_orco_mesh(Object *ob, Mesh *me, BMEditMesh *em, int layer)
+{
+	Mesh *mesh;
+	float (*orco)[3];
+	int free;
+
+	if (em) {
+		mesh = BKE_bmesh_to_mesh_nomain(em->bm, &(struct BMeshToMeshParams){0});
+	}
+	else {
+		BKE_id_copy_ex(NULL, &me->id, (ID**)&mesh,
+			LIB_ID_CREATE_NO_MAIN | LIB_ID_CREATE_NO_USER_REFCOUNT | LIB_ID_CREATE_NO_DEG_TAG, false);
+	}
+
+	orco = get_orco_coords_dm(ob, em, layer, &free);
+
+	if (orco) {
+		BKE_mesh_apply_vert_coords(mesh, orco);
+		if (free) MEM_freeN(orco);
+	}
+
+	return mesh;
+}
+
 static void add_orco_dm(
         Object *ob, BMEditMesh *em, DerivedMesh *dm,
         DerivedMesh *orcodm, int layer)
@@ -1303,6 +1345,48 @@ static void add_orco_dm(
 	}
 }
 
+static void add_orco_mesh(
+        Object *ob, BMEditMesh *em, Mesh *mesh,
+        Mesh *orco_mesh, int layer)
+{
+	float (*orco)[3], (*layerorco)[3];
+	int totvert, free;
+
+	totvert = mesh->totvert;
+
+	if (orco_mesh) {
+		free = 1;
+
+		if (orco_mesh->totvert == totvert) {
+			orco = BKE_mesh_vertexCos_get(orco_mesh, NULL);
+		}
+		else {
+			orco = BKE_mesh_vertexCos_get(mesh, NULL);
+		}
+	}
+	else {
+		/* TODO(sybren): totvert should potentially change here, as ob->data
+		 * or em may have a different number of vertices than dm. */
+		orco = get_orco_coords_dm(ob, em, layer, &free);
+	}
+
+	if (orco) {
+		if (layer == CD_ORCO) {
+			BKE_mesh_orco_verts_transform(ob->data, orco, totvert, 0);
+		}
+
+		if (!(layerorco = CustomData_get_layer(&mesh->vdata, layer))) {
+			CustomData_add_layer(&mesh->vdata, layer, CD_CALLOC, NULL, mesh->totvert);
+			BKE_mesh_update_customdata_pointers(mesh, false);
+
+			layerorco = CustomData_get_layer(&mesh->vdata, layer);
+		}
+
+		memcpy(layerorco, orco, sizeof(float) * 3 * totvert);
+		if (free) MEM_freeN(orco);
+	}
+}
+
 /* weight paint colors */
 
 /* Something of a hack, at the moment deal with weightpaint
@@ -1528,6 +1612,81 @@ static void calc_weightpaint_vert_array(
 	}
 }
 
+static void calc_weightpaint_vert_array_mesh(
+        Object *ob, Mesh *mesh, int const draw_flag, DMWeightColorInfo *dm_wcinfo,
+        unsigned char (*r_wtcol_v)[4])
+{
+	BMEditMesh *em = BKE_editmesh_from_object(ob);
+	const int numVerts = mesh->totvert;
+
+	if ((ob->actdef != 0) &&
+	    (CustomData_has_layer(em ? &em->bm->vdata : &mesh->vdata, CD_MDEFORMVERT)))
+	{
+		unsigned char (*wc)[4] = r_wtcol_v;
+		unsigned int i;
+
+		/* variables for multipaint */
+		const int defbase_tot = BLI_listbase_count(&ob->defbase);
+		const int defbase_act = ob->actdef - 1;
+
+		int defbase_sel_tot = 0;
+		bool *defbase_sel = NULL;
+
+		if (draw_flag & CALC_WP_MULTIPAINT) {
+			defbase_sel = BKE_object_defgroup_selected_get(ob, defbase_tot, &defbase_sel_tot);
+
+			if (defbase_sel_tot > 1 && (draw_flag & CALC_WP_MIRROR_X)) {
+				BKE_object_defgroup_mirror_selection(ob, defbase_tot, defbase_sel, defbase_sel, &defbase_sel_tot);
+			}
+		}
+
+		/* editmesh won't have deform verts unless modifiers require it,
+		 * avoid having to create an array of deform-verts only for drawing
+		 * by reading from the bmesh directly. */
+		if (em) {
+			BMIter iter;
+			BMVert *eve;
+			const int cd_dvert_offset = CustomData_get_offset(&em->bm->vdata, CD_MDEFORMVERT);
+			BLI_assert(cd_dvert_offset != -1);
+
+			BM_ITER_MESH_INDEX (eve, &iter, em->bm, BM_VERTS_OF_MESH, i) {
+				const MDeformVert *dv = BM_ELEM_CD_GET_VOID_P(eve, cd_dvert_offset);
+				calc_weightpaint_vert_color(
+				        (unsigned char *)wc, dv, dm_wcinfo,
+				        defbase_tot, defbase_act, defbase_sel, defbase_sel_tot, draw_flag);
+				wc++;
+			}
+		}
+		else {
+			const MDeformVert *dv = CustomData_get_layer(&mesh->vdata, CD_MDEFORMVERT);
+			for (i = numVerts; i != 0; i--, wc++, dv++) {
+				calc_weightpaint_vert_color(
+				        (unsigned char *)wc, dv, dm_wcinfo,
+				        defbase_tot, defbase_act, defbase_sel, defbase_sel_tot, draw_flag);
+			}
+		}
+
+		if (defbase_sel) {
+			MEM_freeN(defbase_sel);
+		}
+	}
+	else {
+		unsigned char col[4];
+		if ((ob->actdef == 0) && !BLI_listbase_is_empty(&ob->defbase)) {
+			/* color-code for missing data (full brightness isn't easy on the eye). */
+			ARRAY_SET_ITEMS(col, 0xa0, 0, 0xa0, 0xff);
+		}
+		else if (draw_flag & (CALC_WP_GROUP_USER_ACTIVE | CALC_WP_GROUP_USER_ALL)) {
+			copy_v3_v3_char((char *)col, dm_wcinfo->alert_color);
+			col[3] = 255;
+		}
+		else {
+			weightpaint_color(col, dm_wcinfo, 0.0f);
+		}
+		copy_vn_i((int *)r_wtcol_v, numVerts, *((int *)col));
+	}
+}
+
 /** return an array of vertex weight colors from given weights, caller must free.
  *
  * \note that we could save some memory and allocate RGB only but then we'd need to
@@ -1620,6 +1779,80 @@ void DM_update_weight_mcol(
 	}
 }
 
+void mesh_update_weight_mcol(
+        Object *ob, Mesh *mesh, int const draw_flag,
+        float *weights, int num, const int *indices)
+{
+	BMEditMesh *em = BKE_editmesh_from_object(ob);
+	unsigned char (*wtcol_v)[4];
+	int numVerts = mesh->totvert;
+	int i;
+
+	if (em) {
+		BKE_editmesh_color_ensure(em, BM_VERT);
+		wtcol_v = em->derivedVertColor;
+	}
+	else {
+		wtcol_v = MEM_malloc_arrayN(numVerts, sizeof(*wtcol_v), __func__);
+	}
+
+	/* Weights are given by caller. */
+	if (weights) {
+		float *w = weights;
+		/* If indices is not NULL, it means we do not have weights for all vertices,
+		 * so we must create them (and set them to zero)... */
+		if (indices) {
+			w = MEM_calloc_arrayN(numVerts, sizeof(float), "Temp weight array DM_update_weight_mcol");
+			i = num;
+			while (i--)
+				w[indices[i]] = weights[i];
+		}
+
+		/* Convert float weights to colors. */
+		calc_colors_from_weights_array(numVerts, w, wtcol_v);
+
+		if (indices)
+			MEM_freeN(w);
+	}
+	else {
+		/* No weights given, take them from active vgroup(s). */
+		calc_weightpaint_vert_array_mesh(ob, mesh, draw_flag, &G_dm_wcinfo, wtcol_v);
+	}
+
+	if (em) {
+		/* editmesh draw function checks specifically for this */
+	}
+	else {
+		const int totpoly = mesh->totpoly;
+		const int totloop = mesh->totloop;
+		unsigned char(*wtcol_l)[4] = CustomData_get_layer(&mesh->ldata, CD_PREVIEW_MLOOPCOL);
+		MLoop *mloop = mesh->mloop, *ml;
+		MPoly *mp = mesh->mpoly;
+		int l_index;
+		int j;
+
+		/* now add to loops, so the data can be passed through the modifier stack
+		 * If no CD_PREVIEW_MLOOPCOL existed yet, we have to add a new one! */
+		if (!wtcol_l) {
+			wtcol_l = MEM_malloc_arrayN(totloop, sizeof(*wtcol_l), __func__);
+			CustomData_add_layer(&mesh->ldata, CD_PREVIEW_MLOOPCOL, CD_ASSIGN, wtcol_l, totloop);
+		}
+
+		l_index = 0;
+		for (i = 0; i < totpoly; i++, mp++) {
+			ml = mloop + mp->loopstart;
+
+			for (j = 0; j < mp->totloop; j++, ml++, l_index++) {
+				copy_v4_v4_uchar(&wtcol_l[l_index][0],
+				                 &wtcol_v[ml->v][0]);
+			}
+		}
+		MEM_freeN(wtcol_v);
+
+		//dm->dirty |= DM_DIRTY_TESS_CDLAYERS; // XXX: Does Mesh need this?
+	}
+}
+
 static void DM_update_statvis_color(const Scene *scene, Object *ob, DerivedMesh *dm)
 {
 	BMEditMesh *em = BKE_editmesh_from_object(ob);
@@ -1742,6 +1975,32 @@ static void dm_ensure_display_normals(DerivedMesh *dm)
 	}
 }
 
+static void mesh_ensure_display_normals(Mesh *mesh)
+{
+	/* Note: mesh *may* have a poly CD_NORMAL layer (generated by a modifier needing poly normals e.g.).
+	 *       We do not use it here, though. And it should be tagged as temp!
+	 */
+	/* BLI_assert((CustomData_has_layer(&mesh->pdata, CD_NORMAL) == false)); */
+
+	if(mesh->runtime.cd_dirty_vert & CD_MASK_NORMAL || !CustomData_has_layer(&mesh->pdata, CD_NORMAL)) {
+		float (*face_nors)[3] = NULL;
+		face_nors = MEM_malloc_arrayN(mesh->totpoly, sizeof(*face_nors), "face_nors");
+
+		/* if normals are dirty we want to calculate vertex normals too */
+		bool only_face_normals = !(mesh->runtime.cd_dirty_vert & CD_MASK_NORMAL);
+
+		/* calculate face normals */
+		BKE_mesh_calc_normals_poly(
+				mesh->mvert, NULL, mesh->totvert, mesh->mloop, mesh->mpoly,
+				mesh->totloop, mesh->totpoly, face_nors,
+				only_face_normals);
+
+		CustomData_add_layer(&mesh->pdata, CD_NORMAL, CD_ASSIGN, face_nors, mesh->totpoly);
+
+		mesh->runtime.cd_dirty_vert &= ~CD_MASK_NORMAL;
+	}
+}
+
 static void mesh_calc_modifiers(
         struct Depsgraph *depsgraph, Scene *scene, Object *ob, float (*inputVertexCos)[3],
         const bool useRenderParams, int useDeform,
@@ -1749,7 +2008,7 @@ static void mesh_calc_modifiers(
         const int index, const bool useCache, const bool build_shapekey_layers,
         const bool allow_gpu,
         /* return args */
-        DerivedMesh **r_deform, DerivedMesh **r_final)
+        Mesh **r_deform_mesh, Mesh **r_final_mesh)
 {
 	Mesh *me = ob->data;
 	/* Always get the vertex coordinates from the original mesh. Otherwise
@@ -1760,7 +2019,6 @@ static void mesh_calc_modifiers(
 	/* XXX Always copying POLYINDEX, else tessellated data are no more valid! */
 	CustomDataMask mask, nextmask, previewmask = 0, append_mask = CD_MASK_ORIGINDEX;
 	float (*deformedVerts)[3] = NULL;
-	DerivedMesh *dm = NULL, *orcodm, *clothorcodm, *finaldm;
 	int numVerts = me->totvert;
 	const int required_mode = useRenderParams ? eModifierMode_Render : eModifierMode_Realtime;
 	bool isPrevDeform = false;
@@ -1782,7 +2040,6 @@ static void mesh_calc_modifiers(
 	const bool do_mod_wmcol = do_init_wmcol;
 
 	const bool do_loop_normals = (me->flag & ME_AUTOSMOOTH) != 0;
-	const float loop_normals_split_angle = me->smoothresh;
 
 	VirtualModifierData virtualModifierData;
 
@@ -1825,10 +2082,10 @@ static void mesh_calc_modifiers(
 	datamasks = modifiers_calcDataMasks(scene, ob, md, dataMask, required_mode, previewmd, previewmask);
 	curr = datamasks;
 
-	if (r_deform) {
-		*r_deform = NULL;
+	if (r_deform_mesh) {
+		*r_deform_mesh = NULL;
 	}
-	*r_final = NULL;
+	*r_final_mesh = NULL;
 
 	if (useDeform) {
 		if (inputVertexCos)
@@ -1852,7 +2109,7 @@ static void mesh_calc_modifiers(
 				if (!deformedVerts)
 					deformedVerts = BKE_mesh_vertexCos_get(mesh_orig_id, &numVerts);
 
-				modwrap_deformVerts(md, &mectx_deform, NULL, deformedVerts, numVerts);
+				modifier_deformVerts_ensure_normals(md, &mectx_deform, NULL, deformedVerts, numVerts);
 			}
 			else {
 				break;
@@ -1867,14 +2124,17 @@ static void mesh_calc_modifiers(
 		 * places that wish to use the original mesh but with deformed
 		 * coordinates (vpaint, etc.)
 		 */
-		if (r_deform) {
-			*r_deform = CDDM_from_mesh(me);
+		if (r_deform_mesh) {
+			BKE_id_copy_ex(NULL, &me->id, (ID**)r_deform_mesh,
+				LIB_ID_CREATE_NO_MAIN | LIB_ID_CREATE_NO_USER_REFCOUNT | LIB_ID_CREATE_NO_DEG_TAG, false);
 
-			if (build_shapekey_layers)
-				add_shapekey_layers(dm, me, ob);
+			/* XXX: Is build_shapekey_layers ever even true? This should have crashed long ago... */
+			BLI_assert(!build_shapekey_layers);
+			//if (build_shapekey_layers)
+			//	add_shapekey_layers(*r_deform_mesh, me, ob);
 			
 			if (deformedVerts) {
-				CDDM_apply_vert_coords(*r_deform, deformedVerts);
+				BKE_mesh_apply_vert_coords(*r_deform_mesh, deformedVerts);
 			}
 		}
 	}
@@ -1890,9 +2150,9 @@ static void mesh_calc_modifiers(
 	/* Now apply all remaining modifiers. If useDeform is off then skip
 	 * OnlyDeform ones. 
 	 */
-	dm = NULL;
-	orcodm = NULL;
-	clothorcodm = NULL;
+	Mesh *mesh = NULL;
+	Mesh *orco_mesh = NULL;
+	Mesh *cloth_orco_mesh = NULL;
 
 	for (; md; md = md->next, curr = curr->next) {
 		const ModifierTypeInfo *mti = modifierType_getInfo(md->type);
@@ -1907,7 +2167,7 @@ static void mesh_calc_modifiers(
 			continue;
 		}
 
-		if ((mti->flags & eModifierTypeFlag_RequiresOriginalData) && dm) {
+		if ((mti->flags & eModifierTypeFlag_RequiresOriginalData) && mesh) {
 			modifier_setError(md, "Modifier requires original data, bad stack position");
 			continue;
 		}
@@ -1958,26 +2218,24 @@ static void mesh_calc_modifiers(
 		else
 			mask = 0;
 
-		if (dm && (mask & CD_MASK_ORCO))
-			add_orco_dm(ob, NULL, dm, orcodm, CD_ORCO);
+		if (mesh && (mask & CD_MASK_ORCO)) {
+			add_orco_mesh(ob, NULL, mesh, orco_mesh, CD_ORCO);
+		}
 
 		/* How to apply modifier depends on (a) what we already have as
-		 * a result of previous modifiers (could be a DerivedMesh or just
+		 * a result of previous modifiers (could be a Mesh or just
 		 * deformed vertices) and (b) what type the modifier is.
 		 */
 
 		if (mti->type == eModifierTypeType_OnlyDeform) {
 			/* No existing verts to deform, need to build them. */
 			if (!deformedVerts) {
-				if (dm) {
-					/* Deforming a derived mesh, read the vertex locations
+				if (mesh) {
+					/* Deforming a mesh, read the vertex locations
 					 * out of the mesh and deform them. Once done with this
 					 * run of deformers verts will be written back.
 					 */
-					numVerts = dm->getNumVerts(dm);
-					deformedVerts =
-					    MEM_malloc_arrayN(numVerts, sizeof(*deformedVerts), "dfmv");
-					dm->getVertCos(dm, deformedVerts);
+					deformedVerts = BKE_mesh_vertexCos_get(mesh, &numVerts);
 				}
 				else {
 					deformedVerts = BKE_mesh_vertexCos_get(mesh_orig_id, &numVerts);
@@ -1988,45 +2246,46 @@ static void mesh_calc_modifiers(
 			 * to avoid giving bogus normals to the next modifier see: [#23673] */
 			if (isPrevDeform && mti->dependsOnNormals && mti->dependsOnNormals(md)) {
 				/* XXX, this covers bug #23673, but we may need normal calc for other types */
-				if (dm && dm->type == DM_TYPE_CDDM) {
-					CDDM_apply_vert_coords(dm, deformedVerts);
+				if (mesh) {
+					BKE_mesh_apply_vert_coords(mesh, deformedVerts);
 				}
 			}
 
-			modwrap_deformVerts(md, &mectx_deform, dm, deformedVerts, numVerts);
+			modifier_deformVerts_ensure_normals(md, &mectx_deform, mesh, deformedVerts, numVerts);
 		}
 		else {
-			DerivedMesh *ndm;
-
 			/* determine which data layers are needed by following modifiers */
 			if (curr->next)
 				nextmask = curr->next->mask;
 			else
 				nextmask = dataMask;
 
-			/* apply vertex coordinates or build a DerivedMesh as necessary */
-			if (dm) {
+			/* apply vertex coordinates or build a Mesh as necessary */
+			if (mesh) {
 				if (deformedVerts) {
+					/* XXX: What's the point of this copy?
 					DerivedMesh *tdm = CDDM_copy(dm);
 					dm->release(dm);
-					dm = tdm;
+					dm = tdm; */
 
-					CDDM_apply_vert_coords(dm, deformedVerts);
+					BKE_mesh_apply_vert_coords(mesh, deformedVerts);
 				}
 			}
 			else {
-				dm = CDDM_from_mesh(me);
-				ASSERT_IS_VALID_DM(dm);
+				BKE_id_copy_ex(NULL, &me->id, (ID**)&mesh,
+					LIB_ID_CREATE_NO_MAIN | LIB_ID_CREATE_NO_USER_REFCOUNT | LIB_ID_CREATE_NO_DEG_TAG, false);
+				ASSERT_IS_VALID_MESH(mesh);
 
-				if (build_shapekey_layers)
-					add_shapekey_layers(dm, me, ob);
+				// XXX: port to Mesh if build_shapekey_layers can ever be true
+				//if (build_shapekey_layers)
+				//	add_shapekey_layers(mesh, me, ob);
 
 				if (deformedVerts) {
-					CDDM_apply_vert_coords(dm, deformedVerts);
+					BKE_mesh_apply_vert_coords(mesh, deformedVerts);
 				}
 
 				if (do_init_wmcol)
-					DM_update_weight_mcol(ob, dm, draw_flag, NULL, 0, NULL);
+					mesh_update_weight_mcol(ob, mesh, draw_flag, NULL, 0, NULL);
 
 				/* Constructive modifiers need to have an origindex
 				 * otherwise they wont have anywhere to copy the data from.
@@ -2037,45 +2296,48 @@ static void mesh_calc_modifiers(
 				 */
 				if (need_mapping || (nextmask & CD_MASK_ORIGINDEX)) {
 					/* calc */
-					DM_add_vert_layer(dm, CD_ORIGINDEX, CD_CALLOC, NULL);
-					DM_add_edge_layer(dm, CD_ORIGINDEX, CD_CALLOC, NULL);
-					DM_add_poly_layer(dm, CD_ORIGINDEX, CD_CALLOC, NULL);
+					CustomData_add_layer(&mesh->vdata, CD_ORIGINDEX, CD_CALLOC, NULL, mesh->totvert);
+					CustomData_add_layer(&mesh->edata, CD_ORIGINDEX, CD_CALLOC, NULL, mesh->totedge);
+					CustomData_add_layer(&mesh->pdata, CD_ORIGINDEX, CD_CALLOC, NULL, mesh->totpoly);
 
 					/* Not worth parallelizing this, gives less than 0.1% overall speedup in best of best cases... */
-					range_vn_i(DM_get_vert_data_layer(dm, CD_ORIGINDEX), dm->numVertData, 0);
-					range_vn_i(DM_get_edge_data_layer(dm, CD_ORIGINDEX), dm->numEdgeData, 0);
-					range_vn_i(DM_get_poly_data_layer(dm, CD_ORIGINDEX), dm->numPolyData, 0);
+					range_vn_i(CustomData_get_layer(&mesh->vdata, CD_ORIGINDEX), mesh->totvert, 0);
+					range_vn_i(CustomData_get_layer(&mesh->edata, CD_ORIGINDEX), mesh->totedge, 0);
+					range_vn_i(CustomData_get_layer(&mesh->pdata, CD_ORIGINDEX), mesh->totpoly, 0);
 				}
 			}
 
 			
-			/* set the DerivedMesh to only copy needed data */
+			/* set the Mesh to only copy needed data */
 			mask = curr->mask;
 			/* needMapping check here fixes bug [#28112], otherwise it's
 			 * possible that it won't be copied */
 			mask |= append_mask;
-			DM_set_only_copy(dm, mask | (need_mapping ? CD_MASK_ORIGINDEX : 0));
-			
+			mesh_set_only_copy(mesh, mask | (need_mapping ? CD_MASK_ORIGINDEX : 0));
+
 			/* add cloth rest shape key if needed */
 			if (mask & CD_MASK_CLOTH_ORCO)
-				add_orco_dm(ob, NULL, dm, clothorcodm, CD_CLOTH_ORCO);
+				add_orco_mesh(ob, NULL, mesh, orco_mesh, CD_CLOTH_ORCO);
 
 			/* add an origspace layer if needed */
 			if ((curr->mask) & CD_MASK_ORIGSPACE_MLOOP) {
-				if (!CustomData_has_layer(&dm->loopData, CD_ORIGSPACE_MLOOP)) {
-					DM_add_loop_layer(dm, CD_ORIGSPACE_MLOOP, CD_CALLOC, NULL);
-					DM_init_origspace(dm);
+				if (!CustomData_has_layer(&mesh->ldata, CD_ORIGSPACE_MLOOP)) {
+					CustomData_add_layer(&mesh->ldata, CD_ORIGSPACE_MLOOP, CD_CALLOC, NULL, mesh->totloop);
+					mesh_init_origspace(mesh);
 				}
 			}
 
-			ndm = modwrap_applyModifier(md, &mectx_apply, dm);
-			ASSERT_IS_VALID_DM(ndm);
+			Mesh *new_mesh = modifier_applyModifier_ensure_normals(md, &mectx_apply, mesh);
+			ASSERT_IS_VALID_MESH(new_mesh);
 
-			if (ndm) {
-				/* if the modifier returned a new dm, release the old one */
-				if (dm && dm != ndm) dm->release(dm);
+			if (new_mesh) {
+				/* if the modifier returned a new mesh, release the old one */
+				if (mesh && mesh != new_mesh) {
+					BKE_mesh_free(mesh);
+					MEM_freeN(mesh);
+				}
 
-				dm = ndm;
+				mesh = new_mesh;
 
 				if (deformedVerts) {
 					if (deformedVerts != inputVertexCos)
@@ -2085,43 +2347,48 @@ static void mesh_calc_modifiers(
 				}
 			}
 
-			/* create an orco derivedmesh in parallel */
+			/* create an orco mesh in parallel */
 			if (nextmask & CD_MASK_ORCO) {
-				if (!orcodm)
-					orcodm = create_orco_dm(ob, me, NULL, CD_ORCO);
+				if (!orco_mesh) {
+					orco_mesh = create_orco_mesh(ob, me, NULL, CD_ORCO);
+				}
 
 				nextmask &= ~CD_MASK_ORCO;
-				DM_set_only_copy(orcodm, nextmask | CD_MASK_ORIGINDEX |
+				mesh_set_only_copy(orco_mesh, nextmask | CD_MASK_ORIGINDEX |
 				                 (mti->requiredDataMask ?
 				                  mti->requiredDataMask(ob, md) : 0));
 
-				ndm = modwrap_applyModifier(md, &mectx_orco, orcodm);
-				ASSERT_IS_VALID_DM(ndm);
+				new_mesh = modifier_applyModifier_ensure_normals(md, &mectx_orco, orco_mesh);
+				ASSERT_IS_VALID_MESH(new_mesh);
 
-				if (ndm) {
-					/* if the modifier returned a new dm, release the old one */
-					if (orcodm && orcodm != ndm) orcodm->release(orcodm);
-					orcodm = ndm;
+				if (new_mesh) {
+					/* if the modifier returned a new mesh, release the old one */
+					if (orco_mesh && orco_mesh != new_mesh) {
+						BKE_id_free(NULL, orco_mesh);
+					}
+
+					orco_mesh = new_mesh;
 				}
 			}
 
-			/* create cloth orco derivedmesh in parallel */
+			/* create cloth orco mesh in parallel */
 			if (nextmask & CD_MASK_CLOTH_ORCO) {
-				if (!clothorcodm)
-					clothorcodm = create_orco_dm(ob, me, NULL, CD_CLOTH_ORCO);
+				if (!cloth_orco_mesh)
+					cloth_orco_mesh = create_orco_mesh(ob, me, NULL, CD_CLOTH_ORCO);
 
 				nextmask &= ~CD_MASK_CLOTH_ORCO;
-				DM_set_only_copy(clothorcodm, nextmask | CD_MASK_ORIGINDEX);
+				mesh_set_only_copy(cloth_orco_mesh, nextmask | CD_MASK_ORIGINDEX);
 
-				ndm = modwrap_applyModifier(md, &mectx_orco, clothorcodm);
-				ASSERT_IS_VALID_DM(ndm);
+				new_mesh = modifier_applyModifier_ensure_normals(md, &mectx_orco, cloth_orco_mesh);
+				ASSERT_IS_VALID_DM(new_mesh);
 
-				if (ndm) {
-					/* if the modifier returned a new dm, release the old one */
-					if (clothorcodm && clothorcodm != ndm) {
-						clothorcodm->release(clothorcodm);
+				if (new_mesh) {
+					/* if the modifier returned a new mesh, release the old one */
+					if (cloth_orco_mesh && cloth_orco_mesh != new_mesh) {
+						BKE_id_free(NULL, cloth_orco_mesh);
 					}
-					clothorcodm = ndm;
+
+					cloth_orco_mesh = new_mesh;
 				}
 			}
 
@@ -2131,11 +2398,11 @@ static void mesh_calc_modifiers(
 				append_mask |= CD_MASK_PREVIEW_MLOOPCOL;
 			/* In case of active preview modifier, make sure preview mask remains for following modifiers. */
 			else if ((md == previewmd) && (do_mod_wmcol)) {
-				DM_update_weight_mcol(ob, dm, draw_flag, NULL, 0, NULL);
+				mesh_update_weight_mcol(ob, mesh, draw_flag, NULL, 0, NULL);
 				append_mask |= CD_MASK_PREVIEW_MLOOPCOL;
 			}
 
-			dm->deformedOnly = false;
+			// dm->deformedOnly = false; // XXX: Does Mesh need this? Looks to be used only by particle system
 		}
 
 		isPrevDeform = (mti->type == eModifierTypeType_OnlyDeform);
@@ -2152,65 +2419,60 @@ static void mesh_calc_modifiers(
 	for (md = firstmd; md; md = md->next)
 		modifier_freeTemporaryData(md);
 
-	/* Yay, we are done. If we have a DerivedMesh and deformed vertices
-	 * need to apply these back onto the DerivedMesh. If we have no
-	 * DerivedMesh then we need to build one.
+	/* Yay, we are done. If we have a Mesh and deformed vertices
+	 * need to apply these back onto the Mesh. If we have no
+	 * Mesh then we need to build one.
 	 */
-	if (dm && deformedVerts) {
-		finaldm = CDDM_copy(dm);
+	Mesh *final_mesh;
 
-		dm->release(dm);
+	if (mesh) {
+		final_mesh = mesh;
 
-		CDDM_apply_vert_coords(finaldm, deformedVerts);
+		if (deformedVerts) {
+			BKE_mesh_apply_vert_coords(final_mesh, deformedVerts);
+		}
 
 #if 0 /* For later nice mod preview! */
 		/* In case we need modified weights in CD_PREVIEW_MCOL, we have to re-compute it. */
 		if (do_final_wmcol)
-			DM_update_weight_mcol(ob, finaldm, draw_flag, NULL, 0, NULL);
-#endif
-	}
-	else if (dm) {
-		finaldm = dm;
-
-#if 0 /* For later nice mod preview! */
-		/* In case we need modified weights in CD_PREVIEW_MCOL, we have to re-compute it. */
-		if (do_final_wmcol)
-			DM_update_weight_mcol(ob, finaldm, draw_flag, NULL, 0, NULL);
+			mesh_update_weight_mcol(ob, final_mesh, draw_flag, NULL, 0, NULL);
 #endif
 	}
 	else {
-		finaldm = CDDM_from_mesh(me);
-		
-		if (build_shapekey_layers) {
-			add_shapekey_layers(finaldm, me, ob);
-		}
-		
+		BKE_id_copy_ex(NULL, &me->id, (ID**)&final_mesh,
+			LIB_ID_CREATE_NO_MAIN | LIB_ID_CREATE_NO_USER_REFCOUNT | LIB_ID_CREATE_NO_DEG_TAG, false);
+
+		//if (build_shapekey_layers) {
+		//	add_shapekey_layers(final_mesh, me, ob);
+		//}
+
 		if (deformedVerts) {
-			CDDM_apply_vert_coords(finaldm, deformedVerts);
+			BKE_mesh_apply_vert_coords(final_mesh, deformedVerts);
 		}
 
 		/* In this case, we should never have weight-modifying modifiers in stack... */
 		if (do_init_wmcol)
-			DM_update_weight_mcol(ob, finaldm, draw_flag, NULL, 0, NULL);
+			mesh_update_weight_mcol(ob, final_mesh, draw_flag, NULL, 0, NULL);
 	}
 
 	/* add an orco layer if needed */
 	if (dataMask & CD_MASK_ORCO) {
-		add_orco_dm(ob, NULL, finaldm, orcodm, CD_ORCO);
+		add_orco_mesh(ob, NULL, final_mesh, orco_mesh, CD_ORCO);
 
-		if (r_deform && *r_deform)
-			add_orco_dm(ob, NULL, *r_deform, NULL, CD_ORCO);
+		if (r_deform_mesh && *r_deform_mesh)
+			add_orco_mesh(ob, NULL, *r_deform_mesh, NULL, CD_ORCO);
 	}
 
 	if (do_loop_normals) {
 		/* Compute loop normals (note: will compute poly and vert normals as well, if needed!) */
-		DM_calc_loop_normals(finaldm, do_loop_normals, loop_normals_split_angle);
+		BKE_mesh_calc_normals_split(final_mesh);
+		// dm->dirty |= DM_DIRTY_TESS_CDLAYERS; XXX
 	}
 
 	if (sculpt_dyntopo == false) {
 		/* watch this! after 2.75a we move to from tessface to looptri (by default) */
 		if (dataMask & CD_MASK_MFACE) {
-			DM_ensure_tessface(finaldm);
+			// DM_ensure_tessface(final_mesh); // XXX: port?
 		}
 
 		/* without this, drawing ngon tri's faces will show ugly tessellated face
@@ -2223,22 +2485,24 @@ static void mesh_calc_modifiers(
 		 * If using loop normals, poly nors have already been computed.
 		 */
 		if (!do_loop_normals) {
-			dm_ensure_display_normals(finaldm);
+			mesh_ensure_display_normals(final_mesh);
 		}
 	}
 
 	/* Some modifiers, like datatransfer, may generate those data as temp layer, we do not want to keep them,
 	 * as they are used by display code when available (i.e. even if autosmooth is disabled). */
-	if (!do_loop_normals && CustomData_has_layer(&finaldm->loopData, CD_NORMAL)) {
-		CustomData_free_layers(&finaldm->loopData, CD_NORMAL, finaldm->numLoopData);
+	if (!do_loop_normals && CustomData_has_layer(&final_mesh->ldata, CD_NORMAL)) {
+		CustomData_free_layers(&final_mesh->ldata, CD_NORMAL, final_mesh->totloop);
 	}
 
-	*r_final = finaldm;
+	*r_final_mesh = final_mesh;
 
-	if (orcodm)
-		orcodm->release(orcodm);
-	if (clothorcodm)
-		clothorcodm->release(clothorcodm);
+	if (orco_mesh) {
+		BKE_id_free(NULL, orco_mesh);
+	}
+	if (cloth_orco_mesh) {
+		BKE_id_free(NULL, cloth_orco_mesh);
+	}
 
 	if (deformedVerts && deformedVerts != inputVertexCos)
 		MEM_freeN(deformedVerts);
@@ -2246,6 +2510,30 @@ static void mesh_calc_modifiers(
 	BLI_linklist_free((LinkNode *)datamasks, NULL);
 }
 
+static void mesh_calc_modifiers_dm(
+        struct Depsgraph *depsgraph, Scene *scene, Object *ob, float (*inputVertexCos)[3],
+        const bool useRenderParams, int useDeform,
+        const bool need_mapping, CustomDataMask dataMask,
+        const int index, const bool useCache, const bool build_shapekey_layers,
+        const bool allow_gpu,
+        /* return args */
+        DerivedMesh **r_deformdm, DerivedMesh **r_finaldm)
+{
+	Mesh *deform_mesh = NULL, *final_mesh = NULL;
+
+	mesh_calc_modifiers(depsgraph, scene, ob, inputVertexCos, useRenderParams, useDeform,
+			need_mapping, dataMask, index, useCache, build_shapekey_layers, allow_gpu,
+			(r_deformdm ? &deform_mesh : NULL), &final_mesh);
+
+	if(deform_mesh) {
+		*r_deformdm = CDDM_from_mesh_ex(deform_mesh, CD_DUPLICATE);
+		BKE_id_free(NULL, deform_mesh);
+	}
+
+	*r_finaldm = CDDM_from_mesh_ex(final_mesh, CD_DUPLICATE);
+	BKE_id_free(NULL, final_mesh);
+}
+
 float (*editbmesh_get_vertex_cos(BMEditMesh *em, int *r_numVerts))[3]
 {
 	BMIter iter;
@@ -2643,7 +2931,7 @@ static void mesh_build_data(
 	}
 #endif
 
-	mesh_calc_modifiers(
+	mesh_calc_modifiers_dm(
 	        depsgraph, scene, ob, NULL, false, 1, need_mapping, dataMask, -1, true, build_shapekey_layers,
 	        true,
 	        &ob->derivedDeform, &ob->derivedFinal);
@@ -2792,7 +3080,7 @@ DerivedMesh *mesh_create_derived_render(struct Depsgraph *depsgraph, Scene *scen
 {
 	DerivedMesh *final;
 	
-	mesh_calc_modifiers(
+	mesh_calc_modifiers_dm(
 	        depsgraph, scene, ob, NULL, true, 1, false, dataMask, -1, false, false, false,
 	        NULL, &final);
 
@@ -2803,7 +3091,7 @@ DerivedMesh *mesh_create_derived_index_render(struct Depsgraph *depsgraph, Scene
 {
 	DerivedMesh *final;
 
-	mesh_calc_modifiers(
+	mesh_calc_modifiers_dm(
 	        depsgraph, scene, ob, NULL, true, 1, false, dataMask, index, false, false, false,
 	        NULL, &final);
 
@@ -2822,7 +3110,7 @@ DerivedMesh *mesh_create_derived_view(
 	 */
 	ob->transflag |= OB_NO_PSYS_UPDATE;
 
-	mesh_calc_modifiers(
+	mesh_calc_modifiers_dm(
 	        depsgraph, scene, ob, NULL, false, 1, false, dataMask, -1, false, false, false,
 	        NULL, &final);
 
@@ -2837,7 +3125,7 @@ DerivedMesh *mesh_create_derived_no_deform(
 {
 	DerivedMesh *final;
 	
-	mesh_calc_modifiers(
+	mesh_calc_modifiers_dm(
 	        depsgraph, scene, ob, vertCos, false, 0, false, dataMask, -1, false, false, false,
 	        NULL, &final);
 
@@ -2851,7 +3139,7 @@ DerivedMesh *mesh_create_derived_no_deform_render(
 {
 	DerivedMesh *final;
 
-	mesh_calc_modifiers(
+	mesh_calc_modifiers_dm(
 	        depsgraph, scene, ob, vertCos, true, 0, false, dataMask, -1, false, false, false,
 	        NULL, &final);
 
@@ -3149,6 +3437,76 @@ void DM_init_origspace(DerivedMesh *dm)
 	BLI_array_free(vcos_2d);
 }
 
+static void mesh_init_origspace(Mesh *mesh)
+{
+	const float default_osf[4][2] = {{0, 0}, {1, 0}, {1, 1}, {0, 1}};
+
+	OrigSpaceLoop *lof_array = CustomData_get_layer(&mesh->ldata, CD_ORIGSPACE_MLOOP);
+	const int numpoly = mesh->totpoly;
+	// const int numloop = mesh->totloop;
+	MVert *mv = mesh->mvert;
+	MLoop *ml = mesh->mloop;
+	MPoly *mp = mesh->mpoly;
+	int i, j, k;
+
+	float (*vcos_2d)[2] = NULL;
+	BLI_array_staticdeclare(vcos_2d, 64);
+
+	for (i = 0; i < numpoly; i++, mp++) {
+		OrigSpaceLoop *lof = lof_array + mp->loopstart;
+
+		if (mp->totloop == 3 || mp->totloop == 4) {
+			for (j = 0; j < mp->totloop; j++, lof++) {
+				copy_v2_v2(lof->uv, default_osf[j]);
+			}
+		}
+		else {
+			MLoop *l = &ml[mp->loopstart];
+			float p_nor[3], co[3];
+			float mat[3][3];
+
+			float min[2] = {FLT_MAX, FLT_MAX}, max[2] = {-FLT_MAX, -FLT_MAX};
+			float translate[2], scale[2];
+
+			BKE_mesh_calc_poly_normal(mp, l, mv, p_nor);
+			axis_dominant_v3_to_m3(mat, p_nor);
+
+			BLI_array_clear(vcos_2d);
+			BLI_array_reserve(vcos_2d, mp->totloop);
+			for (j = 0; j < mp->totloop; j++, l++) {
+				mul_v3_m3v3(co, mat, mv[l->v].co);
+				copy_v2_v2(vcos_2d[j], co);
+
+				for (k = 0; k < 2; k++) {
+					if (co[k] > max[k])
+						max[k] = co[k];
+					else if (co[k] < min[k])
+						min[k] = co[k];
+				}
+			}
+
+			/* Brings min to (0, 0). */
+			negate_v2_v2(translate, min);
+
+			/* Scale will bring max to (1, 1). */
+			sub_v2_v2v2(scale, max, min);
+			if (scale[0] == 0.0f)
+				scale[0] = 1e-9f;
+			if (scale[1] == 0.0f)
+				scale[1] = 1e-9f;
+			invert_v2(scale);
+
+			/* Finally, transform all vcos_2d into ((0, 0), (1, 1)) square and assing them as origspace. */
+			for (j = 0; j < mp->totloop; j++, lof++) {
+				add_v2_v2v2(lof->uv, vcos_2d[j], translate);
+				mul_v2_v2(lof->uv, scale);
+			}
+		}
+	}
+
+	//mesh->dirty |= DM_DIRTY_TESS_CDLAYERS; // XXX: Needed for Mesh?
+	BLI_array_free(vcos_2d);
+}
 
 
 /* derivedmesh info printing function,

source/blender/blenkernel/intern/mesh_validate.c

@@ -972,7 +972,7 @@ bool BKE_mesh_validate_all_customdata(CustomData *vdata, CustomData *edata,
 }
 
 /**
- * \see  #DM_is_valid to call on derived meshes
+ * Validates and corrects a Mesh.
  *
  * \returns true if a change is made.
  */
@@ -1011,6 +1011,42 @@ int BKE_mesh_validate(Mesh *me, const int do_verbose, const int cddata_check_mas
 	}
 }
 
+/**
+ * Checks if a Mesh is valid without any modification. This is always verbose.
+ *
+ * \see  #DM_is_valid to call on derived meshes
+ *
+ * \returns is_valid.
+ */
+bool BKE_mesh_is_valid(Mesh *me)
+{
+	const bool do_verbose = true;
+	const bool do_fixes = false;
+
+	bool is_valid = true;
+	bool changed = true;
+
+	is_valid &= BKE_mesh_validate_all_customdata(
+	        &me->vdata, &me->edata, &me->ldata, &me->pdata,
+	        false,  /* setting mask here isn't useful, gives false positives */
+	        do_verbose, do_fixes, &changed);
+
+	is_valid &= BKE_mesh_validate_arrays(
+	        me,
+	        me->mvert, me->totvert,
+	        me->medge, me->totedge,
+	        me->mface, me->totface,
+	        me->mloop, me->totloop,
+	        me->mpoly, me->totpoly,
+	        me->dvert,
+	        do_verbose, do_fixes,
+	        &changed);
+
+	BLI_assert(changed == false);
+
+	return is_valid;
+}
+
 /**
  * Check all material indices of polygons are valid, invalid ones are set to 0.
  * \returns is_valid.

source/blender/blenkernel/intern/modifier.c

@@ -901,6 +901,19 @@ void modifier_deformVerts(struct ModifierData *md, const ModifierEvalContext *ct
 	}
 }
 
+void modifier_deformVerts_ensure_normals(struct ModifierData *md, const ModifierEvalContext *ctx,
+	struct Mesh *mesh,
+	float (*vertexCos)[3], int numVerts)
+{
+	const ModifierTypeInfo *mti = modifierType_getInfo(md->type);
+	BLI_assert(!mesh || CustomData_has_layer(&mesh->pdata, CD_NORMAL) == false);
+
+	if (mesh && mti->dependsOnNormals && mti->dependsOnNormals(md)) {
+		BKE_mesh_calc_normals(mesh);
+	}
+	modifier_deformVerts(md, ctx, mesh, vertexCos, numVerts);
+}
+
 void modifier_deformMatrices(struct ModifierData *md, const ModifierEvalContext *ctx,
 	struct Mesh *mesh,
 	float (*vertexCos)[3], float (*defMats)[3][3], int numVerts)
@@ -993,6 +1006,18 @@ struct Mesh *modifier_applyModifier(struct ModifierData *md, const ModifierEvalC
 	}
 }
 
+struct Mesh *modifier_applyModifier_ensure_normals(struct ModifierData *md, const ModifierEvalContext *ctx,
+	struct Mesh *mesh)
+{
+	const ModifierTypeInfo *mti = modifierType_getInfo(md->type);
+	BLI_assert(CustomData_has_layer(&mesh->pdata, CD_NORMAL) == false);
+
+	if (mti->dependsOnNormals && mti->dependsOnNormals(md)) {
+		BKE_mesh_calc_normals(mesh);
+	}
+	return modifier_applyModifier(md, ctx, mesh);
+}
+
 struct Mesh *modifier_applyModifierEM(struct ModifierData *md, const ModifierEvalContext *ctx,
 	struct BMEditMesh *editData,
 	struct Mesh *mesh)